Poster: Ecophysiology
Abs #
13: Identification, accumulation, and functional prediction of novel tomato transcripts systemically up-regulated after fire damage
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Presenter: |
Coker, Jeffrey S, jeffreycoker@hotmail.com |
Authors | Coker, Jeffrey S (A) Davies, Eric (B) Vian, Alain (A) | | Affiliations: |
(A): North Carolina State University
(B): Unité Associée Université Blaise Pascal-Institut National de la Recherche Agronomique, Organisation et Variabilité des Génomes Végétaux
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Despite the major impacts of fire on plants, responses to fire damage have not been closely studied on the level of gene expression. Here we present analyses of novel transcripts from tomato (Lycopersicon esculentum) which are systemically up-regulated in leaves after a distant leaf is wounded by flame. Nine cDNA fragments were isolated from a subtractive cDNA library of leaf tissue 1 hour after flaming. Using data mining and PCR, full-length open reading frames were predicted, amplified, and then sequenced. Comparisons with the Arabidopsis genome suggested that 8 of the encoded proteins are slow-evolving. Real-time RT-PCR using leaf RNA after flaming confirmed the systemic accumulation of 4 and 7 transcripts within 30 and 60 minutes, respectively, before returning to basal levels within 3 hours. During this same timecourse, proteinase inhibitor I levels gradually increased over 30-fold in 6 hours. Expression analyses also showed that 8 of the transcripts are present in unwounded leaf, stem, and root tissues. The predicted proteins include an acyl carrier, adenylyl sulfate reductase, PS II oxygen-evolving complex protein 3, anion:sodium symporter, chloroplast-specific ribosomal protein, and an unknown wound/stress-related protein. Homologues of several of these proteins have been associated with other types of wound and stress responses. Nevertheless, it appears that within an hour after being damaged by fire, plants systemically up-regulate a variety of genes involved with basic cell metabolism and upkeep, in addition to classic defense genes such as proteinase inhibitors.
